read_file_lines

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description must disclose behavioral traits. It only states the purpose but does not describe performance with large files, error handling, security implications (only hinted by projectRoot param), or whether the tool modifies state. As a read operation, it likely does not mutate data, but this is not stated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, clear phrase with no extraneous words. It is front-loaded and efficient, though it could include more information without becoming verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 6 parameters and no output schema, the description is incomplete. It does not explain return values, behavior when lines are out of range, how aroundPattern interacts with startLine/endLine, or error scenarios. An agent would need more context to use it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema descriptions cover 100% of parameters, so the baseline is 3. The description adds minimal extra meaning beyond the schema; it summarizes that the tool reads line ranges, but the schema already specifies startLine, endLine, aroundPattern, etc. No additional semantic context is provided.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Read specific line ranges from a file' clearly states the action (read) and the resource (line ranges from a file). It is specific enough to distinguish from sibling tools like batch_read or read_file_surgical, though it does not explicitly call out differences.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives. There is no mention of conditions, exclusions, or context that would help an agent decide between this and similar tools like read_file_surgical or parse_file.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.